Villain Dirty Den is often hailed as one of soap's most iconic characters

A spokeswoman for Leslie confirmed to The Sun: “It’s true that Leslie is very poorly.”

The London-born actor was famously brought back from the dead by EastEnders bosses in 2003 when his character Den was reunited with on-screen daughter Sharon Watts in one of the soap’s most shocking ever storylines.

Fourteen years earlier, he was supposedly shot dead by a canal during an attempted bid to leave the country and Sharon even identified his body.

Leslie’s portrayal as an EastEnders villain was made more believable by the fact he spent a decade behind bars from 1967 for the murder of a German taxi driver.